Fig. 2.

Diversity and taxonomic analysis along the sports season in non-concussed football athletes. (a) Plots of Beta diversity analysis of the fecal microbiota from athletes who did not experience a diagnosed concussion during the football season. The Principal Coordinate Analysis (PCoA) ordination plot was based on Weighted UniFrac distances for the mid- (n ​= ​29, blue), post- (n ​= ​22, yellow), and off-season (n ​= ​21, gray) groups. Confidence ellipses represent the 95% confidence interval for each timepoint. Group dissimilarities were evaluated by Analysis of Similarity (ANOSIM). (b) Shannon and Simpson alpha diversity indices at the species level for the mid- (n ​= ​29, blue), post- (n ​= ​22, yellow), and off-season (n ​= ​21, gray) timepoints. In the box and whisker plots, the cross represents the mean. Significance was determined by Kruskal-Wallis followed by Dunn's multiple comparisons test. (c) Relative abundances of the top 15 phyla, families, and genera in the fecal microbiota of the non-concussed athletes through the mid- (n ​= ​29, blue), post- (n ​= ​22, yellow), and off- (n ​= ​21, gray) seasons. (d) Heatmap of the log2 fold changes for the species that are significantly altered across the sport season in the non-concussed athletes. Statistical testing by random-effects multivariate analysis included the samples from athletes who participated in all collection timepoints (n ​= ​17). All statistically significant changes were identified between the post- and off-season. (e) Relative abundances at the mid- (n ​= ​17, blue), post- (n ​= ​17, yellow), and off-season (n ​= ​17, gray) timepoints of the prevalent taxa (abundance >1% in at least one of the groups at the family and genus level, >0.1% at the species level) showing significant alterations in the random-effects multivariate analysis. In the box and whisker plots, the cross represents the mean. ∗q ​< ​0.05; ∗∗∗q ​< ​0.001.